The fortress on Anhatomirim Island was part of a triangular defensive system along with the Fortresses of São José da Ponta Grossa and Santa Cruz de Ratones.
The Guiana dolphin population in this area is one of the most studied groups of the species in the Southern Hemisphere.
The Fortress of Santa Cruz was occupied by Brazilian revolutionary forces during the 1893 Federalist Revolution.
The architecture follows the 'Vauban' influence adapted for tropical colonial defense.
The protection area covers over 6,000 hectares of marine and island territory.
The Anhatomirim Environmental Protection Area is a protected marine and terrestrial reserve encompassing the islands of Anhatomirim, Ratones Grande, and São Francisco de Paula. It serves as a critical habitat for the resident population of Guiana dolphins (Sotalia guianensis), a species frequently observed in the surrounding waters. The primary cultural anchor of the site is the Fortress of Santa Cruz of Anhatomirim, an 18th-century defensive structure constructed by the Portuguese to protect the entrance to the bay of Florianópolis. The area is managed as part of a coastal preservation system designed to balance archaeological heritage with environmental conservation. Visitors can access the islands via boat excursions originating from neighboring mainland coastal towns. The ecosystem features Atlantic Forest remnants and provides essential breeding and resting grounds for various sea birds. Infrastructure on Anhatomirim island includes preserved colonial military barracks, cannons, and defensive bastions. Restrictions on water sports and vessel speeds are enforced to minimize disturbance to the marine mammal populations. Scientific research and environmental monitoring are core functions of this protected zone.
The upper ramparts of the Fortress of Santa Cruz looking back toward the mainland coast.
Bring polarized sunglasses to better spot dolphins breaking the water surface.
Apply high-SPF sunscreen, as there is limited shade on the stone walkways of the fortress.
Ensure your camera battery is fully charged, as the site offers few power outlets.
Attempting to swim or touch the dolphins; using drones, which are strictly regulated or prohibited in the protected air zone.
Operations are highly dependent on sea conditions and weather; boat services may be suspended during heavy storms.
Maintain silence when near identified dolphin pods; follow marked paths to protect historical masonry and native vegetation.
